Secure Boot and Restricted Boot.
Mar. 26th, 2013 07:25 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
mjg59I gave a presentation at Libreplanet this weekend on the topic of Secure Boot and Restricted Boot. There's a copy of the video here - it should be up on the conference site at some point. It turned out to be excellent timing, in that a group in Spain filed a complaint with the European Commission this morning arguing that Microsoft's imposition of Secure Boot on the x86 client PC market is anticompetitive. I suspect that this is unlikely to succeed (the Commission has already stated that the current implementation appears to conform to EU law), and I fear that it's going to make it harder to fight the real battle we face.
Secure Boot means different things to different people. I think the FSF's definition is a useful one - Secure Boot is any boot validation scheme in which ultimate control is in the hands of the owner of the device, while Restricted Boot is any boot validation scheme in which ultimate control is in the hands of a third party. What Microsoft require for x86 Windows 8 devices falls into the category of Secure Boot - assuming that OEMs conform to Microsoft's requirements, the user must be able to both disable Secure Boot entirely and also leave Secure Boot enabled, but with their own choice of trusted keys and binaries. If the FSF set up a signing service to sign operating systems that met all of their criteria for freeness, Microsoft's requirements would permit an end user to configure their system such that it refused to run non-free software. My system is configured to trust things shipped by Fedora or built locally by me, a decision that I can make because Microsoft require that OEMs support it. Any system that meets Microsoft's requirements is a system that respects the freedom of the computer owner to choose how restrictive their computer's boot policy is.
This isn't to say that it's ideal. The lack of any common UI or key format between hardware vendors makes it difficult for OS vendors to document the steps users must take to assert this freedom. The presence of Microsoft as the only widely trusted key authority leaves people justifiably concerned as to whether Microsoft will be equally aggressive in blacklisting its own products as it will be in blacklisting third party ones. Implementation flaws in a (very) small number of systems have resulted in correctly signed operating systems failing to boot, requiring users to update their firmware before being able to install anything but Windows.
But concentrating on these problems misses the wider point. The x86 market remains one where users are able to run whatever they want, but the x86 market is shrinking. Users are purchasing tablets and other ARM-based ultraportables. Some users are using phones as their primary computing device. In contrast to the x86 market, Microsoft's policies for the ARM market restrict user freedom. Windows Phone and Windows RT devices are required to boot only signed binaries, with no option for the end user to disable the signature validation or install their own keys. While the underlying technology is identical, this differing set of default policies means that Microsoft's ARM implementation is better described as Restricted Boot. The hardware vendors and Microsoft define which software will run on these systems. The owner gets no say.
And, unfortunately, Microsoft aren't alone. Apple, the single biggest vendor in this market, implement effectively identical restrictions. Some Android vendors provide unlockable bootloaders, but others (either through personal preference or at the behest of phone carriers) lock down their platforms. A naive user is likely to end up purchasing a device that will, in the absence of exploited security flaws, refuse to run if any system components are modified. Even in cases where the underlying components are built using free software, there's no guarantee that the user will have the ability to assert any of those freedoms.
Why does this matter? Some of these platforms (notably Windows RT and iOS, but also some Android-based devices) will even refuse to run unsigned applications. Users are unable to write their own software and distribute it to others without agreeing to often onerous restrictions. Users with the misfortune of living in the wrong country may be forbidden from even that opportunity. The vendor may choose to block applications that compete with their own, reducing innovation. The ability to explore and tinker with the components of the system is restricted, making it harder for users to learn how modern operating systems work. If I own a perfectly functional phone that no longer receives vendor updates, I don't even have the option of paying a third party to ensure that I can't be compromised by a malicious website and risk the loss of passwords or financial details. The user is directly harmed by these restrictions.
I won't argue that there are no benefits to curated software ecosystems. I won't even argue against devices shipping with a locked down policy by default. I will strongly argue that the owner of a device should not only have the freedom to choose whether they wish to remain within those locked-down boundaries, but should also have the freedom to impose their own boundaries. There should be no forced choice between freedom and security.
Those who argue against Secure Boot risk depriving us of the freedom to make a personal decision as to who we trust. Those who argue against Secure Boot while ignoring Restricted Boot risk depriving us of even more. The traditional PC market is decreasing in importance. Unless we do anything about it, free software will be limited to a niche group of enthusiasts who've carefully chosen from a small set of devices that respect user freedom. We should have been campaigning against Restricted Boot 10 years ago. Don't delay it even further by fighting against implementations that already respect user freedom.
Secure Boot means different things to different people. I think the FSF's definition is a useful one - Secure Boot is any boot validation scheme in which ultimate control is in the hands of the owner of the device, while Restricted Boot is any boot validation scheme in which ultimate control is in the hands of a third party. What Microsoft require for x86 Windows 8 devices falls into the category of Secure Boot - assuming that OEMs conform to Microsoft's requirements, the user must be able to both disable Secure Boot entirely and also leave Secure Boot enabled, but with their own choice of trusted keys and binaries. If the FSF set up a signing service to sign operating systems that met all of their criteria for freeness, Microsoft's requirements would permit an end user to configure their system such that it refused to run non-free software. My system is configured to trust things shipped by Fedora or built locally by me, a decision that I can make because Microsoft require that OEMs support it. Any system that meets Microsoft's requirements is a system that respects the freedom of the computer owner to choose how restrictive their computer's boot policy is.
This isn't to say that it's ideal. The lack of any common UI or key format between hardware vendors makes it difficult for OS vendors to document the steps users must take to assert this freedom. The presence of Microsoft as the only widely trusted key authority leaves people justifiably concerned as to whether Microsoft will be equally aggressive in blacklisting its own products as it will be in blacklisting third party ones. Implementation flaws in a (very) small number of systems have resulted in correctly signed operating systems failing to boot, requiring users to update their firmware before being able to install anything but Windows.
But concentrating on these problems misses the wider point. The x86 market remains one where users are able to run whatever they want, but the x86 market is shrinking. Users are purchasing tablets and other ARM-based ultraportables. Some users are using phones as their primary computing device. In contrast to the x86 market, Microsoft's policies for the ARM market restrict user freedom. Windows Phone and Windows RT devices are required to boot only signed binaries, with no option for the end user to disable the signature validation or install their own keys. While the underlying technology is identical, this differing set of default policies means that Microsoft's ARM implementation is better described as Restricted Boot. The hardware vendors and Microsoft define which software will run on these systems. The owner gets no say.
And, unfortunately, Microsoft aren't alone. Apple, the single biggest vendor in this market, implement effectively identical restrictions. Some Android vendors provide unlockable bootloaders, but others (either through personal preference or at the behest of phone carriers) lock down their platforms. A naive user is likely to end up purchasing a device that will, in the absence of exploited security flaws, refuse to run if any system components are modified. Even in cases where the underlying components are built using free software, there's no guarantee that the user will have the ability to assert any of those freedoms.
Why does this matter? Some of these platforms (notably Windows RT and iOS, but also some Android-based devices) will even refuse to run unsigned applications. Users are unable to write their own software and distribute it to others without agreeing to often onerous restrictions. Users with the misfortune of living in the wrong country may be forbidden from even that opportunity. The vendor may choose to block applications that compete with their own, reducing innovation. The ability to explore and tinker with the components of the system is restricted, making it harder for users to learn how modern operating systems work. If I own a perfectly functional phone that no longer receives vendor updates, I don't even have the option of paying a third party to ensure that I can't be compromised by a malicious website and risk the loss of passwords or financial details. The user is directly harmed by these restrictions.
I won't argue that there are no benefits to curated software ecosystems. I won't even argue against devices shipping with a locked down policy by default. I will strongly argue that the owner of a device should not only have the freedom to choose whether they wish to remain within those locked-down boundaries, but should also have the freedom to impose their own boundaries. There should be no forced choice between freedom and security.
Those who argue against Secure Boot risk depriving us of the freedom to make a personal decision as to who we trust. Those who argue against Secure Boot while ignoring Restricted Boot risk depriving us of even more. The traditional PC market is decreasing in importance. Unless we do anything about it, free software will be limited to a niche group of enthusiasts who've carefully chosen from a small set of devices that respect user freedom. We should have been campaigning against Restricted Boot 10 years ago. Don't delay it even further by fighting against implementations that already respect user freedom.
Sure-Fire Way To Install $OS_OF_YOUR_CHOICE
Date: 2013-09-01 07:18 pm (UTC)1. download a bootable usbkey image of the distro of your choice
2. burn it (preferably straight from the browser with no save-then-locate-then-open-burner-app steps), without overwriting any data already on the usbkey in question
3. if still booted into win8 on the target device, tells you to save & close & reboot ... but booting into win8 on the target device is *not* in any way required, you can always use a usbkey/dvd/cd/whatnot that you created on some other system, or purchased, or whatever
4. upon booting the target device, the bios autodetects multiple bootable media (internal drive + external usbkey ... and supports booting from usb3 as well as from usb2 might I add), automatically *asks* you whether to boot from internal hdd/ssd or from new usbkey/cd/dvd (not forcing you to hit F12 or somesuch... although by default there can be a 15-second countdown and then it boots from the internal media), offering appropriate names ("original win8" versus "new linux $DISTRO installer" rather than hardware-chipset-names). If there is a SecureBoot blockage, the BIOS warns you of the trouble, but when you confirm you want to install Linux anyways, makes it *easy* for you to add the new digisig into your device, preferably pulling it automagically straight from the linux boot-media ... much like a firmware-flash-update but less drastic. (Ideally it would also help you create a personal self-signed digisig, but that is above and beyond the call of duty.)
5. upon selecting the linux installer, and getting confirmation, it automagically clonezillas your existing setup, automagically uses parted to adjust your internal hdd/ssd appropriately, installs grub, automagically installs your distro for you with appropriate defaults, downloads the latest security patches from the internet, sets your timezone using geolocation, detects your lang&keyb from the bios/win8 installation, and *then* takes you into the full distro for 'final configuration' steps (no rebooting required)
6. this final stage might involve uninstalling some of the auto-packages, or adding some non-auto-packages, or just tweaking settings (plus confirming the automagic choices made during silent-install were not borked).
Obviously, this one-size-fits-all approach is no good for sysadmins at a large ISP, or developers working with complex hypervisor setups, or what not... but those folks can take care of themselves (and putting this Tillie-infrastructure in place will help the tech-savvy folks do *their* job more efficiently as well as making it *easy* for Tony to get his laptop booting Linux -- no muss and no fuss).
Re: Sure-Fire Way To Install $OS_OF_YOUR_CHOICE
Date: 2013-09-01 07:27 pm (UTC)The firmware doesn't do this.
The firmware and system vendors had no interest in doing this.
So yeah, it'd be easier if things worked that way, but they don't and they're not going to.
Re: Sure-Fire Way To Install $OS_OF_YOUR_CHOICE
Date: 2013-09-01 07:45 pm (UTC)As you point out, the firmware vendor (AMI and friends) and system vendors (Dell/HP/Lenovo/Samsung/friends) were against such things, back when the current firmware spec-standards were developed. And I agree that getting anything changed under win8 is not-gonna-happen-no-way-no-how. I'm more interested in a few years from now.
Besides the Linux distros, there are other interested parties that might support some variant of my easy-to-add-new-digisig proposal, circa 2015. By then, google will have Android slash ChromeOS pushing into the mid-range laptop market. By then, there will be at least four major tablet OSes: win9, iOS, android-slash-chromeOS, ubuntuTouch-or-waylandPi, and at least *some* consumers will want the ability to crossgrade amongst those choices, rather than be stuck with a phone or tablet that won't be upgradeable. That's the biggest takeaway from the Tony-thread: plenty of people were mad that they *thought* the machine might be locked down that way, whether it was technically true or not. (Contrast that with the world of smartphones, where locked-down iPhone never used to raise eyebrows. Maybe that sentiment is shifting?)
Part of the reason that Linux got the short end of the stick in UEFI/SecureBoot was because we were reactionary, not proactive, methinks. I'd like to fix that, next time around.